Genetius

The study characterizes a plasma membrane-localized, calcium‑permeable force‑gated channel named Rapid Mechanically Activated (RMA) in plants, using patch‑clamp and pressure‑clamp to elucidate its rapid activation, inactivation, and irreversible adaptation upon repeated mechanical stimulation. Kinetic modeling shows the channel functions as a pass‑band filter for frequencies between 10 Hz and 1 kHz, supporting its role in transducing high‑frequency mechano‑stimuli such as insect vibrations.

The study used single‑cell transcriptomics to compare Arabidopsis thaliana leaf cell responses during pattern‑triggered and effector‑triggered immunity, revealing that core defense modules are broadly shared but differ in timing, intensity, and cell‑type specific receptor dynamics. Distinct mesophyll subpopulations showed divergent resilience patterns, and gene regulatory network analysis identified WRKY‑regulated and salicylic‑acid biosynthesis modules, with the cue1-6 mutant confirming robustness of core immune responses while exposing cryptic sucrose‑responsive pathways.

The study resolves the ectodomain structure of the plant-specific LRR‑RLK CARD1 (HPCA1) and reveals a surface‑exposed copper ion coordinated by histidines that is essential for hydrogen peroxide signaling. Combined structural, genetic, and biochemical analyses show that previously identified cysteine residues are not required for signal perception, establishing CARD1 as the first copper‑dependent redox receptor.

The study reveals that a conserved clade of pentatricopeptide repeat (PPR) genes in Arabidopsis thaliana generates secondary siRNAs that contribute to plant immunity, with these PPR loci undergoing extensive duplication and diversification to create a varied siRNA pool for pathogen defense. This PPR‑siRNA system is proposed as a novel family of defense genes with potential for engineering broad‑spectrum disease resistance.

The study evaluated the genetically encoded redox biosensor roGFP2-Orp1 for monitoring extracellular redox dynamics in diverse land plants, revealing that re‑oxidation rates in the apoplast differ between Physcomitrium patens and Arabidopsis thaliana and are accelerated by immune activation. Comparisons across tip‑growing cells showed no intracellular redox gradient but a partially reduced extracellular sensor in Nicotiana tabacum pollen tubes, indicating species‑ and cell‑type‑specific oxidative processes.

The study examined five sequential organ abscission events in two cherry species, revealing that some abscission zones form de novo while others are pre‑formed and reactivated by localized ethylene signaling, leading to cell division, lignification, ROS accumulation, and pH changes. Species‑specific differences were found in petal shedding and a post‑fertilization checkpoint that eliminates small fruits, indicating a hierarchical, multilayered reproductive filter controlling fruit set.

The study visualizes subcellular dynamics following activation of the NRC4 resistosome, showing that NRC4 enrichment at the plasma membrane triggers calcium influx, followed by sequential disruption of mitochondria, plastids, endoplasmic reticulum, and cytoskeleton, culminating in plasma membrane rupture and cell death. These observations define a temporally ordered cascade of organelle and membrane events that execute plant immune cell death.

The study reconstitutes Papaver rhoeas self‑incompatibility (SI) in Arabidopsis thaliana by expressing the pollen S‑determinant PrpS, revealing that SI triggers a rapid Ca2+‑dependent signaling cascade that leads to mitochondrial H2O2 production, metabolic collapse, and programmed cell death. Using a genetically encoded H2O2 sensor and metabolic assays, the authors show that early mitochondrial disruption, driven by altered Ca2+, cytosolic pH, and distinct ROS sources, is central to the SI response.

The study identified a suppressor mutation (sune42) in the Golgi-localized Ca2+ transporter CCX4 that alleviates the dominant‑negative root hair phenotype caused by the extensin‑less LRX1ΔE14 protein in Arabidopsis. Detailed Ca2+ imaging showed that LRX1ΔE14 disrupts tip‑focused cytoplasmic Ca2+ oscillations, a defect rescued by the sune42 mutation, highlighting the role of Golgi‑mediated Ca2+ homeostasis in root hair growth.

The study compared two plasma‑activated water (PAW) solutions with different H₂O₂ levels, produced by a radio‑frequency glow discharge, on Arabidopsis thaliana growth and stress responses. PAW lacking detectable H₂O₂ promoted seedling growth and induced nitrogen‑assimilation genes, while H₂O₂‑containing PAW did not affect growth but enhanced root performance under heat stress; mature plants fertilized with H₂O₂‑free PAW performed comparably to nitrate controls. These results indicate PAW can replace NO₃⁻ fertilizers provided H₂O₂ levels are carefully managed.